Screening apparatus



May 13, 1930.

w. .1.l GARRlsoN SCREENING APPARATUS Filed Feb. 28, 1929 vMl* . Wzfarfaon Patented May 13, 193@ russes SCREENING- APPARATUS Application led February 28, 1929. Serial No. 343,384;

This invention relates to improvements in screening apparatus for the removal of flat particles from any material, and more parf ticularly to improvements in the construction of apparatus for use in screening gravel.

An important object of the invention is to produce a structure which, with but slight modifi-cation of the screens of existing shaker tables, may be readily applied to the shaker tables and will serve to separate objectionable thin and flat particles from any material being screened.

- A further and more specific object of the invention is to provide a screening structure invwhich these flats are separated from gravel in the ordinary process of screening and are passed longitudinally of the screen to a suitable discharge point.

A still further object of the invention is the provision of a structure of this character in'which the separa-ting element or elements are adjustable to enable determination of the size of the flats which will be discharged from a given screen deck in single or multi deck screening apparatus.

These and other objects I attain by the construction shown in the accompanying` drawing, wherein for'the purpose of illustration is shown a preferred embodiment of vmy invention and wherein Figure 1 is a fragmentary perspective View showing screening and separating apparatus constructed in accordance with my invention;

Figure 2 is a fragmentary side elevation thereof;

Figure 3 is a fragmentary sectional View therethrough showing a slightly modified form of screen surface.

Referring now more particularly7 to the drawing, the numeral 10 generally designates the side walls of a screen housing and 11 the woven screen unit which may be agitated in 4any suitable manner. These screensincline longitudinally and in accordance with my invention, are centrally crowned either by placing the opposite sides of the screen at an angle to one another, as shown in Figure 1, or by arcuately curving the screen, as indicated in Figure 3. Extending over each screen are supports 12, the ends of which are secured to the separator walls, as indicated at 13. Eachk support 12 is provided with vertically err.

ltending' portions 13a overlying the screen in spaced relation thereto and in spaced relation to the sidewalls. rThese vertically extending portions which are preferably provided by offsetting the support are abutted by longitudinal separator plates V14.

Each support 12 has formed in each of the vertically extending portions 13EL thereof an angularl slot 15 through which a bolt 16 carried by the associated plate extends.

It will be obvious that by loosening these bolts and shifting the plates longitudinally, the space of the lower edges of the plates from the screen may be regulated.

The screens outwardly of the plates 14 are preferably constructed to prevent the passage of flats which pass under the separating plates 14 but will pass material smaller than .the flats thus separated. This is preferably accomplished-by increasing the number of longitudinal wires or bars in the portions of the screen lying outwardly of the plates 14, thus decreasing the size of the mesh outwardly of the plates 14. This construction is more clearly illustrated ineFigures land 3. In the operation of the device, the material is discharged at the top end of the screen at the center thereof'7 and due to the crown of the screen and the inclination thereof, said material tends to move transversely of the screen as it moves longitudinally thereof` This will cause they material to `tend to bank up against the plates 14, and thin, flat. particles in the material being treated will work out through the slots 19 under thelower edges of the plates 14 to the alleyways 17 provided between these plates 14 and the opposed walls 10 of the separator. The material passing to the alleyways'will passV longitudinally of the Ascreen to a discharge outlet 18 which may, as illustrated7 be disposed at the end of the separator. l y.

I It will-be obvious that the particular means of adjustment provided for the separator plates 14 and herein illustrated and the particular method employed for causing material to move transversely of the screen and come into coacting engagement with the sepn means associated with-the screen for venting passage of material through th varator platesVV 14 may be Vmodified considerv ably without in any manner departing from screen outwardly of said plates.

2. In combination, a separator screen having at least a portion of its surfacetransversely inclined to cause travel of the material to one side thereof, plates supported L above and extending; longitudinally of the screen and having their lower edges in spaced relation tothe screen, and means limiting transverse movement of material uponv the screen after its passage beneath said plates, the mesh of `said screen being decreased` outwardly of said plates. Y

3. In combination, a separator screen having at least a. portion of its surface transverselyl inclined to lcause travel of the material ,to one side thereof, plates supported above and extending longitudinally of the verse movement of material upon the screen after its passage beneath said plates, means `associated with the screen vfor preventingV screen and having their lower edges in. spaced relation to the screen, Vmeans limiting transpassage of material through the screen outwardly of said plates, and means, for adjust- Ving said plates toward and away from the screen. Y

,l 4t. In combination, a separator screen having at least a po-rtion of its surface transversely inclined to cause travel of the material to one side thereof, plates supported above and extending longitudinally of the screen and having their lower edges in spaced relation toV the screen, means limiting transverse movement of materialV upon the screen after its passage beneath saidplates, the mesh of said screen being dec-reased'outwardly of said plates,A and means for adjusting said plates toward and away from the screen.

5. In a separator, parallel side walls, a longitudinally inclined screen extending between said side walls and having its edges fixed thereto and supported therefrom, said screen being transversely crowned, supports extending transversely. over the-screen and secured at their ends to said side walls, andA plates extending'downwardlv from said supports, said plates being in slightly spaced relation to the side walls and having their lower edges in slightly spaced relation to the screen.

6. In a separator, parallel side walls, a longitudinally inclined screen extending between said side walls and having its edges supported therefrom, said screen being transversely crowned, supports extending transversely over the screen and secured at their ends to said side walls, and plates extending downwardly from said supports, said plates being in slightly spaced relation to the side walls and lhaving their lower edges in slightly spaced relation to the screen, the edges of the screen outwardly of said plates being formed to prevent passage of the coarser flat material therethrough.

7. In a separator, parallel side walls, a longitudinally inclined screen extending be-k tween said side walls and having its edges supported therefrom, said screen being transversely crowned, supports extending transversely over kthe screen and secured at their ends to said side walls, plates extending downwardly from said supports, said plates being in slightly spaced relation to the side walls and having their lower edges in slightly spaced relation to the screen, the edges of the screen outwardly of said plates being formed to prevent passage of the coarser flat material therethrough, and means for aolliusting the plates toward and away fromv the screen@ Y In testimony whereof I hereunto aiiix myv signature.

WILLIAM J. GARRisoN. 

